1. Field of the Invention
The present invention relates to a coaxial electrical connector, especially a right angle coaxial electrical connector.
2. Description of the Related Art
As for the right angle electrical connector, the one disclosed in Patent Reference JP 2001-43939 is known.
As shown in FIG. 5, the connector 50 of the Patent Reference is fitted and connected onto the counter connector 60, which is arranged on a circuit board P, in the direction vertical to the circuit board. The counter connector 60 has a cylindrical outer conductor 61, a center conductor 62 arranged in the center of the outer conductor 61, and a dielectric 63 which is molded between those conductors as a unitary piece. The outer conductor 61 is formed to have a cylindrical shape by rolling and jointing two edges of a metal sheet piece. The outer conductor 61 has a locking groove 61A on the outer circumferential surface. The center conductor 62 has a rod-like contact section 62A, and a connecting section 62B which is formed as an L-shape arm extending from the lower end of the contact section 62A. The dielectric 63 is arranged only in lower portion of the counter connector 60. Above the dielectric 63, an annular receiving space is formed between the outer conductor 61 and the contact section 62A of the center conductor 62.
The outer conductor 51 of the connector 50 which is fitted and connected onto the counter connector 60 has a cylindrical fitting section 51A, a cover section 51B, a frame-like section 51C, and a cable holding section 51D. The outer conductor 51 is made by punching and bending a metal sheet to form the shape. As also shown in FIG. 6, the cylindrical fitting section 51A has a jointing section 51A1 at its upper half portion, and has a cylindrical shape. An annular protrusion 51E for locking the fitting of the connectors is provided on the inner surface of the cylindrical fitting section 51A by making an annular groove on the outer surface of the cylindrical fitting section 51A. A plurality of slits 51F is provided at the lower half portion of the cylindrical fitting section 51A along its circumferential direction, so as to cross the annular protrusion 51E. The frame-like section 51C is provided so as to protrude in the radial direction of the fitting section 51A from a part of the upper portion of the fitting section 51A.
The outer conductor 51 holds the dielectric 52, while the dielectric 52 holds a terminal 53, which is a center conductor of the connector 50. As shown in FIG. 6, the cover section 51B and the holding section 51D of the outer conductor 51 are provided opposite the frame-like section 51C in the radial direction, and extend upward from the upper edge of the cylindrical fitting section 51A. After the dielectric 52 and the terminal 53 which is already connected to a cable are held in the cylindrical fitting section 51A, the cover section 51B and the surrounding section 51D are bent downward for 90 degree, as shown in FIG. 5. The cover section 51B and the cylindrical fitting section 51A are connected via a narrow linking section 51G, where the cover section 51B is bent. The dielectric 52 holds the terminal 53, and has a terminal hole 52A to house spring contact sections 53A of the terminal 53. The dielectric 52 also has a tongue 52B which extends upward and can be bent at its base and a cable receiving section-52D having a cable guiding groove 52C. The tongue 52B is bent being pressed by the cover section 51B of the outer conductor 51, while it slides over the inner surface of the cover section 51B along the extending direction (longitudinal direction) of the tongue 52B.
In this connector 50, as shown in FIG. 6, after the core-wire C1 of the coaxial cable C is connected by soldering onto the upper surface of the terminal 53, the contact sections 53A of the terminal 53 are inserted into the terminal hole 52A of the dielectric 52. Then, the outer conductor 51 is bent at the linking section 51G while pushing the tongue 52B of the dielectric 52 (See FIG. 5), and then the holding section 51D is bent so as to tightly hold the frame-like section 51C and the cable C.
Once the connector 50 is fitted onto the counter connector 60, the contact sections 53A of the terminal of the connector 50 contact with the center conductor 62 of the connector 60 by pinching it. While the cylindrical fitting section 51A of the outer conductor 51 of the connector 50 enlarges its diameter, it contacts with the outer circumferential surface of the outer conductor 61 of the connector 60, and the connector 50 is locked not to come off by the fitting of the annular protrusion 51E to the annular locking groove 61A.
In the connector of the Patent Reference, when the tongue 52B of the dielectric 52 is bent being pushed by the cover section 51B of the outer conductor 51, since the inner surface of the cover section 51B is flat, the tongue 52B can slide obliquely over the inner surface of the cover section, as shown with the dashed line having one long dash and two short dashes in FIG. 7. The sliding off of the tongue can be occurred even by slight asymmetry in the strength of the tongue 52B, or by slight asymmetry in the pressure applied by the cover section. With those slight asymmetries, the tongue could unacceptably slide off. If the tongue is in a wrong position and pressed by the cover section, the tongue cannot be correctly placed in the groove on the upper surface of the main body of the dielectric, so that the cover section is held unstably above the intended position. In this case, the dimension of the connector in the height direction can be larger than the intended dimension, and also the holding of the tongue can be unstable. In some cases, the electrical properties of the connector can be deteriorated by the sliding off of the tongue.
Furthermore, the sizes of electrical devices have been dramatically reduced in these years, and in case of the connector, the dimension in the height direction, i.e. the dimension in the fitting direction, is required to be small. In case of the connector disclosed in the Patent Reference 1, however, since the inner surface of the cover section is flat, even if the tongue is correctly bent at the correct position without sliding off, the thicknesses of the cover section and the tongue are added above the main body of the dielectric, so that the profile of the connector cannot be reduced.